Calculate Acreage With Our Sqft to Acres Calculator

To calculate acreage, multiply the length of your lot by its width in feet, then divide the total square feet (sq ft) by 43,560 . A 165 × 330 ft lot covers 54,450 sq ft (5,058.6 m²), which comes to 1.25 acres (0.51 hectares). Odd shapes need one extra step. You split those parcels into triangles or trapezoids, work out each piece, and add the results before converting.

Square Feet to Acres Calculator

Our square feet to acres calculator turns any lot measurement into acres and hectares the moment you enter it . It accepts 4 input types:

• Length and width in feet, yards, or meters for rectangular lots
• Four side lengths plus one diagonal for irregular four-sided parcels
• Total square footage copied from a deed, plat map, or county record
• Price per acre (optional) for a total land-value estimate

One formula drives every result: Acres = Square Feet ÷ 43,560. The tool multiplies acreage by price per acre if you fill in that field, so a 1.25-acre lot listed at $18,000 per acre returns $22,500. Metric works differently. Square meters get divided by 4,046.86 instead.

How Many SF in an Acre?

One acre holds exactly 43,560 square feet, which equals 4,046.86 square meters (m²) or 0.4047 hectares (ha). On listings, SF and sq ft mean the same thing. That odd number traces back to English surveyors, who fixed the acre at 1 chain wide by 1 furlong long, or 66 × 660 ft. Shape doesn’t change the total. A square acre measures 208.7 ft (63.6 m) per side, while a lot only 100 ft wide needs 435.6 ft (132.8 m) of depth to reach the same area.

How to Calculate Acreage in 3 Steps

To calculate acreage of a rectangular lot, multiply length by width, then divide the product by 43,560 .

1. Measure the length and width in feet. Pull figures from a property survey or plat map first, and use a 100 ft tape or measuring wheel if neither document exists.
2. Multiply length by width to get total square footage.
3. Divide the square footage by 43,560 to convert sqft to acres.

Here’s a real case: a 165 × 330 ft homesite. Multiplying the sides gives 54,450 sq ft, and dividing by 43,560 lands on exactly 1.25 acres. Round only at the final step. Rounding each side first compounds the error on big tracts, where a few feet per line can swing the result by hundreds of square feet.

Sqft to Acres Conversion Table

To convert square feet to acres, divide the square footage by 43,560 , and multiply acres by 43,560 to reverse it.

How to Calculate Acreage of an Irregular Lot

To calculate acreage of an irregular lot, split the parcel into triangles or trapezoids, then divide their combined area by 43,560 . Four side lengths can’t settle the area on their own. Two lots with identical sides of 300, 210, 260, and 180 ft enclose different areas once their corner angles shift, which is why surveyors record at least one diagonal or one angle.

Triangle Method (Heron’s Formula)

Use the triangle method if your lot has 4 straight sides but no right angles. Measure every side plus the diagonal from corner A to corner C, which cuts the lot into 2 triangles. Heron’s formula finds each triangle’s area from its 3 sides:

Take sides AB = 300 ft, BC = 210 ft, CD = 260 ft, and DA = 180 ft, with a 330 ft diagonal. Triangle ABC comes to 30,864 sq ft. Triangle ACD adds 23,294 sq ft, for a combined 54,158 sq ft, or 1.24 acres (0.50 ha).

Trapezoid Method

Lots that widen toward the back fit the trapezoid formula: Area = (front + back) ÷ 2 × depth . A parcel 200 ft wide at the street and 250 ft wide at the rear, with 445 ft of depth, covers 100,125 sq ft. That converts to 2.30 acres (0.93 ha). Depth means the perpendicular distance between the 2 parallel lines, so measure straight across if the side boundaries slant. Curved creek banks and winding road frontage defeat both formulas, and a mapping tool handles those better.

How Do You Calculate Acreage From a Map or GPS?

You calculate acreage from a map by tracing the property boundary as a closed polygon in a tool that reports area automatically . Four free options work well:

• Google Earth Pro: open the Ruler tool, pick the Polygon tab, and read the area in acres once the shape closes.
• County GIS (Geographic Information System) parcel viewer: view recorded lot lines, and check the deeded-acres field many counties publish.
• Google Maps on desktop: right-click, choose Measure distance, and click the first point again to see total area.
• GPS field apps: walk the boundary with your phone while the app plots each corner.

Phone GPS has limits, though. GPS-enabled smartphones typically land within 16 ft (4.9 m) of the true position under open sky, and tree cover or nearby buildings widen that gap. On a square 1-acre lot, a 10 ft error along one side shifts the total by about 2,087 sq ft. That’s close to 5%.

How to Calculate Acreage From a Legal Description

To calculate acreage from a Public Land Survey System (PLSS) description, start with 640 acres and multiply by each fraction listed . Consider a deed reading “NE¼ of the SW¼ of Section 12.” Multiplying 640 × ¼ × ¼ gives 40 acres (16.2 ha), the classic quarter-quarter section. The Bureau of Land Management (BLM) oversees PLSS records, which span major portions of 30 southern and western states. Not every section is perfect, though. Sections along a township’s north and west edges often run over or under 640 acres, so check the official plat for numbered lots.

Texas and the original 13 states rely on metes and bounds instead, a chain of bearings and distances that walks the boundary from a starting point. Older deeds there use colonial-era units:

• Chain: 66 ft (20.1 m), with 10 square chains equal to 1 acre
• Rod (also called a pole or perch): 16.5 ft (5.03 m)
• Link: 7.92 in (20.1 cm)

Once every call is converted to feet, the triangle method handles the rest.

How Accurate Is Each Acreage Method?

DIY methods land within a few percent, while only a licensed boundary survey carries legal weight.

Hire a licensed land surveyor if the acreage sets a sale price or settles a boundary dispute. A typical suburban boundary survey runs $450 to $950 this year, while rural tracts of 10 to 40 acres cost $1,500 to $5,000 (surveyors.io). Older records carry one quirk. The National Institute of Standards and Technology (NIST) retired the U.S. survey foot after December 31, 2022, so pre-2023 coordinates can differ from current ones by 2 parts per million.

Hectares to Acres Conversion

One hectare equals 2.471 acres, and one acre equals 0.405 hectares. Multiply hectares by 2.471 to get acres.

What Common Acreages Look Like (Square Dimensions)

If a parcel were a perfect square, these are the side lengths. Real lots are rarely square, so use the calculator above for your exact shape.

Worked Examples

How many acres is 108,900 square feet? Divide by 43,560: 108,900 ÷ 43,560 = 2.5 acres.

What would a 400 ft × 500 ft lot cost at $900 per acre? 400 × 500 = 200,000 sq ft. 200,000 ÷ 43,560 = 4.59 acres. 4.59 × $900 ≈ $4,132.

How many acres is a lot with four unequal sides? Pick the four-sided shape in the calculator above and enter all four sides plus one diagonal; it splits the lot into two triangles and adds their areas.

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